# Renchu Song (slim)

> Renchu Song is epsilla co-founder and former CEO; now HarnessRouter co-founder/CTO. Epsilla Vector Database on Anchor Terminal, with grades, an about and public profiles.

- Full: https://www.anchorterminal.com/people/renchu-song/index.md (~900 tokens) · this version ~630 tokens · JSON https://www.anchorterminal.com/people/renchu-song/index.json · canonical https://www.anchorterminal.com/people/renchu-song/
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · MCP: https://www.anchorterminal.com/mcp · Updated: 2026-10-28
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)

Epsilla co-founder and former CEO; now HarnessRouter co-founder/CTO.

Renchu (Richard) Song co-founded Epsilla, an AI agent platform, and is now co-founder and CTO of HarnessRouter, a unified interface for agent harnesses.

- LinkedIn: https://www.linkedin.com/in/renchu-richard-song-a4099247

## What Renchu builds

- [Epsilla Vector Database](https://www.anchorterminal.com/tools/epsilla.md), graded F, 35.9/100, in Retrieval & vector search. Open-source (GPL-3.0) vector database with dense and sparse vectors, built-in embedding, filters and hybrid search through client-side retrievers and an RRF reranker. Epsilla co-founder and former CEO; now HarnessRouter co-founder/CTO, researched 2026-10-27.

## Backed by

- [Y Combinator](https://www.anchorterminal.com/investors/y-combinator/)

## Questions

### Who is Renchu Song?

Renchu (Richard) Song co-founded Epsilla, an AI agent platform, and is now co-founder and CTO of HarnessRouter, a unified interface for agent harnesses.

### What does Epsilla (founder now at HarnessRouter; merger reported on own profile) make?

Anchor Terminal lists Epsilla Vector Database from Epsilla (founder now at HarnessRouter; merger reported on own profile).

### Who has invested in Epsilla (founder now at HarnessRouter; merger reported on own profile)?

The sources our research read name Y Combinator.

### How are Renchu's tools graded?

Epsilla Vector Database is graded F, 35.9 out of 100, on Anchor Terminal's benchmark, which scores every listing against the same checklist.

## Sources

- https://www.ycombinator.com/launches/J8t-epsilla-a-10x-faster-open-source-vector-database
- https://www.ycombinator.com/founders/14642-richard-song
- https://www.linkedin.com/in/renchu-richard-song-a4099247
- https://www.epsilla.com/
- https://www.epsilla.com
- https://github.com/epsilla-cloud
- https://x.com/epsilla_inc
- https://github.com/epsilla-cloud/vectordb
- https://www.epsilla.com/sla

These are the people building the tools we list, named for their public role in the company or project behind a listing, from public pages, with the date it was researched.